278 TREES OF NORTH AMERICA 



dark chestnut-brown in drying, with a narrow ring of hoary pubescence at the apex, 

 inclosed at the base only in a thin shallow cup-shaped cup light green and pubescent 

 on the inner surface, covered on the outer by small acute and usually thin or some- 

 times, especially in the south, thicker tumid scales coated with pale pubescence or 

 tomentum and ending in thin reddish brown tips. 



A tree, usually 50-60, rarely 80-90 high, with a trunk 3-^ in diameter, 

 short stout branches spreading nearly at right angles and forming a dense round- 

 topped symmetrical head, stout branchlets brittle at the joints, coated at first with 

 short dense hoary tomentum, dark gray or reddish brown and tomentose, pubescent, 

 or puberulous during their first winter, becoming ultimately ashy gray or dark 

 brown; frequently not more than 20-30 high, and sometimes, especially south- 

 ward, shrubby in habit. Winter-buds ovate, obtuse, \'-$' long, with light rather 

 bright red pubescent scales. Bark '-!' thick, generally pale, and covered by small 

 scales sometimes tinged with brown or light red. Wood hard, heavy, strong, brittle, 

 dark brown, becoming nearly black with exposure, with thick light brown sapwood ; 

 largely used as fuel. 



Distribution. Scattered over low hills, dry mountain slopes and valleys; Cali- 

 fornia, Mendocino County, and the upper valley of the Sacramento River, southward 

 along the western slopes of the Sierra Nevada up to elevations of 4000, and through 

 valleys of the coast ranges to the Tehachapi Pass and the borders of the Mohave 

 Desert; most abundant and of its largest size in the valleys between the coast moun- 

 tains and the interior ridges of the coast ranges south of the Bay of San Francisco. 



-tt-Leaves mostly persistent until the appearance of those of the following spring. 

 ++Leaves blue-green. 



40. Quercus Engelmanni, Greene. Evergreen Oak. 



Leaves oblong to obovate, usually obtuse and rounded or sometimes acute at the 

 apex, gradually or abruptly wedge-shaped or rounded or cordate at the base, entire, 



often undulate, or sinuate-toothed, with occasionally rigid teeth, or at the ends of 

 sterile branches frequently coarsely crenately serrate, with incurved teeth, or rarely 

 lobed, with acute oblique rounded lobes, when they unfold bright red and coated 



